Compensating Device for Nonwoven Fabric Speed Fluctuations

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Solution Overview

Problem

Existing fiber processing technologies face challenges in effectively compensating for fluctuating conveying speeds of nonwoven fabrics, leading to inconsistent web guidance and storage capacity, which affects the reliability and precision of the processing operation.

Innovation Solution

A compensating device with an endless storage belt featuring multiple deflection points forms a polygon shape, allowing for adjustable sag and storage capacity control by altering the location of deflection points and using active or passive adjustment devices to manage speed differences and tension, ensuring precise web guidance and adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the storage capacity of the storage belt is increased to compensate for speed differences, then the reliability of web guidance is improved, but the device complexity increases due to additional deflection points and adjustment mechanisms

Engineering Contradiction:
Improveweb guidance reliabilityVSAvoidcompensation device complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic adjustability of the storage capacity by allowing the lower deflection point to be repositioned along the storage belt. This enables the system to adapt the sag magnitude and storage capacity according to actual speed difference requirements, making the device flexible rather than fixed. The dynamic adjustment mechanism resolves the contradiction by allowing the system to use minimal complexity only when necessary while maintaining high reliability when speed compensation is needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the geometric parameter of the storage belt configuration by varying the position of the lower deflection point. This parameter change directly affects the sag magnitude and storage capacity, enabling continuous adjustment of compensation performance. By changing this key parameter, the system achieves reliable web guidance across varying operating conditions without requiring multiple fixed configurations.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If the sag magnitude is increased to provide larger storage capacity, then the compensation capability for speed differences is improved, but the control precision becomes more difficult to maintain

Engineering Contradiction:
Improvefleece storage capacityVSAvoidsag control precision
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent incorporates a detection device that monitors the actual position of the lower deflection point and provides feedback to the control system. This feedback mechanism enables closed-loop control of the sag magnitude, ensuring that the desired storage capacity is achieved and maintained. The feedback control compensates for deviations and maintains precision even when operating with large sag magnitudes for maximum storage capacity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual or purely mechanical adjustment methods with an automated control system that uses detection devices and actuators. This substitution enables precise control of the deflection point position and sag magnitude, overcoming the limitations of mechanical precision when dealing with large adjustments. The automated system maintains control precision regardless of the sag magnitude.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Stability of the object's composition

If the storage belt is tensioned tightly to improve web adhesion, then the web guidance stability is improved, but the storage capacity decreases due to reduced sag

Engineering Contradiction:
Improveweb guidance stabilityVSAvoidfleece storage capacity
Core Design Contradiction:
Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

The patent makes the tension and sag magnitude dynamically adjustable rather than fixed. By allowing the lower deflection point to be repositioned, the system can dynamically balance between tension (for stability) and sag (for storage capacity). This dynamic capability resolves the contradiction by enabling the system to optimize the tension-sag balance according to actual operating conditions, maintaining both stability and adequate storage capacity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the storage belt into distinct runs (upper, lower, and side runs) with different functional requirements. The upper run carries the web with adequate sag for storage, while the lower run can be tensioned independently through the adjustable deflection point. This segmentation allows different parts of the belt to have different tension levels, maintaining web guidance stability without compromising storage capacity in the upper run.

Inventive Principle:
Principle #1Segmentation

4Productivity

If the conveying speed is increased to improve productivity, then the processing efficiency is improved, but the speed differences between upstream and downstream equipment increase, requiring larger storage capacity

Engineering Contradiction:
Improvefiber plant productivityVSAvoidstorage capacity requirement
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent implements dynamic adjustment of the storage capacity by repositioning the lower deflection point based on the conveying speed and speed differences. When high productivity requires high conveying speeds and large speed differences, the system dynamically increases the sag magnitude to provide adequate storage capacity. This dynamic adaptation allows the system to maintain high productivity without being constrained by fixed storage capacity limitations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the geometric parameter of the storage belt configuration (the position of the lower deflection point) in response to varying productivity requirements. This parameter change enables continuous adjustment of storage capacity to match the storage needs at different conveying speeds, allowing the system to optimize both productivity and storage capacity rather than being limited by a fixed configuration.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2893069B2Device for compensating variable transport speeds of a nonwoven fabric
Publication Date: 2023.03.15 HI TECH TEXTILE HOLDING GMBH
  • EP2893069B2 patent drawingFigure 1
  • EP2893069B2 patent drawingFigure 2
  • EP2893069B2 patent drawingFigure 3

AI summary

The invention relates to a compensating device (1) for fluctuating transport speeds of a fibre nonwoven (3). The compensating device (1) has a buffer belt (2) driven in a loop with three or four or more deflection points (12, 13, 14, 15, 16) and with a variable sag (11) of the carrying run supporting the fibre nonwoven (3). The compensating device (1) further comprises an adjusting element (19) for adjusting the location of at least one deflecting point (15, 16).